This invention relates in general to apparatus and processes for fabricating flexible belts.
Various techniques have been devised to fabricate belts from flexible tubes. One difficulty with cutting flexible tubes is the need to prevent collapse of the tube during the cutting operation. This problem has been addressed, for example, by using centrifugal force to expand an expandable tube against the interior of a rotating support cylinder. The segment projecting beyond one end of the rotation support cylinder may be cut by a knife. Unfortunately, for tubes that have a delicate outer surface that must be protected from damage during processing, damage can occur to the outer surface due to abrasive contact between the outer surface of the flexible tube and the inner surface of the support cylinder during acceleration of the tube to expand it and during deceleration of the tube in preparation for removal of the tube from the support cylinder.
Reinforced belts have been cut from a belt-band by supporting the belt-band on two parallel cylinders that are moved away from each other to stretch the belt-band for cutting. Each end of each cylinder is supported to maintain the parallel relationship of the cylinders during stretching of the belt-band. This approach is time consuming and cumbersome because at least one end of each cylinder must be separated from its support to permit loading and unloading of the belt-band from the cylinders. Moreover, at least one of the cylinders must be sequentially moved toward, away from, and toward the other cylinder to permit loading stretching and unloading, respectively, of the Belt-band.
Belts can also be prepared from continuous webs by slicing the webs lengthwise, cutting the sliced webs into short segments and thereafter welding opposite ends of the webs together. Unfortunately, this involves a batch process that consumes considerable time, requires duplicate manual handling, occupies excessive floor space and necessitates extensive equipment for alignment, cutting, welding trimming and other processing steps. In addition, the resulting belt has a seam which is highly undesirable for many applications.